Fix notebook tab switching with keyboard if some pages are hidden

When switching the current notebook tab, we need to take only visible
pages into account.  If we don't and we try switching to an invisible
page, nothing happens.

In practice, the issue is visible on the message window notebook if one
of the tabs are hidden due to one of the "msgwin_*_visible" settings.
Mark Geany.txt with filetype

Since we have a reStructuredText filetype, mark doc file so it
automatically opens with the right filetype.
Return a non-printing sequence for no context separators

Function symbols_get_context_separator() returns the symbol
separator for the language, but some languages do not have
symbol context separators, for example markup languages like
Asciidoc.  To prevent the symbols pane wrongly detecting and
acting on a valid character sequence as a separator, return a
non-printing character which should not occur.

Options "" and NULL not used as they break some code and would
need an ABI bump.

Other languages can be added as they are identified.
Fix some widgets packing issues under GTK3 in the preference dialog
Adding owner and serial to list of keywords for SQL
Merge NEWS from 1.23.1 release
file browser: Fix capitalization in menu item

Closes #3613558.
Add ellipsis to menu items requiring further user input

This is a very common paradigm used by GNOME, KDE, MacOSX, Windows,
etc., and following it makes our UI more consistent with these and
easier to use by their users.

https://developer.gnome.org/hig-book/stable/menus-design.html.en#menu-item-type-command

Closes #3613494.
Fix internationalization of the File Properties dialog title
Small update of the French translation
Use Glade to create the File Properties dialog
Updated Hebrew translation

Signed-off-by: Frank Lanitz <flanitz@bgc-jena.mpg.de>
Update Scintilla to version 3.3.2
Update for new Scintilla styles
Merge branch 'scintilla-update'
Remove use of some of our own deprecated Scintilla wrappers

Remove most obvious calls to our very own deprecated Scintilla wrapper
functions sci_get_text(), sci_get_text_range() and
sci_get_selected_text().

Some calls are still left, but they either really benefit from these
functions or the fix would be more complex.
Adding comment (postgres) as a SQL-keyword.
Updated Hebrew translation

for the commit "Use Glade to create the File Properties dialog"

Signed-off-by: Frank Lanitz <flanitz@bgc-jena.mpg.de>
Updating NEWS-file a bit with recent changes done by frlan
Update of German translation